A new monoalkyl glycerol ether, 3-(n-henicosyloxy) propane-1,2-diol (1), was isolated from the CH2Cl2/MeOH crude extract of the Red Sea soft coral Nephthea mollis. Additionally, three known related analogues were identified: chimyl alcohol (2), batyl alcohol (3), and 3-(icosyloxy) propane-1,2-diol (4). The chemical structure of 3-(n-henicosyloxy) propane-1,2-diol was determined using advanced spectroscopic analyses, including 1D, 2D Nuclear Magnetic Resonance (NMR), Electron Ionization mass spectra (EI-MS), and High-Resolution Electron Spray Ionization mass spectra (HRESIMS) analyses. Furthermore, the identification of chimyl alcohol, batyl alcohol and 3-(icosyloxy) propane-1,2-diol was achieved by studying their EI mass fragmentation analyses and comparing their mass data with those previously reported in the literature. The cytotoxic activity of the Nephthea mollis crude extract and 3-(n-henicosyloxy) propane-1,2-diol was evaluated against five human cancer cell lines: HepG2 (hepatocellular carcinoma), MCF-7 (breast carcinoma), NCI-1299 (lung carcinoma), HeLa (cervical cancer cell), and HT-29 (colon adenocarcinoma). Moreover, 3-(n-henicosyloxy) propane-1,2-diol revealed moderate cytotoxicity against the HeLa cell line with an IC50 value of 24.1 μM, while showing inactivity against the remaining cell lines (IC50 >100 μM).
Monthly Archives: September 2023
Sequential recognition of bisulfate and acetate by ruthenium complex: Experimental and theoretical studies
New complex [RuLCl2(PPh3)] (L= N,N-bis(2-hydroxy-5-nitrobenzaldehyde)-2,2’-diaminodiethylamine) was prepared and characterized analytically. [RuLCl2(PPh3)] was employed as a luminescent chemosensor for the detection of anions. The results show that [RuLCl2(PPh3)] can detect HSO4 ̄ and AcO ̄ selectively with sequential order in H2O-CH3CN (8:2, v/v) at pH 7.0. The spectral binding, titration, and interference analyses reveal that the addition of HSO4 ̄ to [RuLCl2(PPh3)] emits a distinguished fluorescence intensity (IF/I0= 6.55) significantly. This shows that HSO4 ̄ interacts suitably with the complex to switch ON the fluorescence which could be explained by inhibition of a PET mechanism as the above addition forms [RuLCl(HSO4)(PPh3)] in the excited state. Selectivity of [RuLCl2(PPh3)] with HSO4 ̄ forms [RuLCl(HSO4)(PPh3)] in the water showing a negligible change in its emission except for AcO ̄, which enhances fluorescence intensity. For the addition of AcO ̄ to [RuLCl2(PPh3)] forms [RuLCl(AcO)(PPh3)], however, the adding of HSO4 ̄ to [RuLCl(AcO)(PPh3)] does not show any change in the intensity, suggesting that there exists a logic gate function for the addition of HSO4 ̄ followed by AcO ̄ to [RuLCl2(PPh3)]. This finding is interesting because [RuLCl2(PPh3)] can act as a fast selective chemosensor for the sequential detection of HSO4 ̄ and AcO ̄.
An overview of heterogeneous transition metal‐based catalysts for cyclohexene epoxidation reaction
Cyclohexane epoxide with highly active epoxy groups is an important intermediate in the preparation of fine chemicals. However, the epoxidation path of cyclohexene is difficult to be controlled due to the allyl oxidation of cyclohexene and the ring opening of cyclohexane epoxide in the process of cyclohexene epoxidation to cyclohexane oxide. This work mainly reviewed the structure-activity relationships and synthesis processes of a series of heterogeneous transition metal-based catalysts based on cyclohexene epoxidation reaction, including molybdenum(Mo)-based, tungsten(W)-based, vanadium(V)-based, titanium(Ti)-based, cobalt(Co)-based,, etc. catalysts. First, the mechanism of cyclohexene epoxidation by transition metal-based catalysts was collated from the perspective of catalytic active centers. Then, the current status of research on cyclohexene epoxidation catalysts was summarized from the perspective of catalyst support. At the same time, the differences between alkyl hydroperoxide, hydrogen peroxide (H2O2), and oxygen (O2) as oxidants were analyzed. Finally, the main factors affecting the catalytic performance were summarized and the reasonable opinions on the design of catalysts were put forward. The above work provided some scientific support for the development of olefin epoxidation industry.
Catalyst‐ and Substrate‐Controlled Regiodivergent Synthesis of Carbazoles through Gold‐Catalyzed Cyclizations of Indole‐Functionalized Alkynols
A wide variety of regioselectively substituted carbazole derivatives can be synthesized by the gold-catalyzed cyclization of alkynols bearing an indol-3-yl and an additional group at the homopropargylic positions. The regioselectivity of the process can be controlled by both the oxidation state of the gold catalyst and the electronic nature of the substituents of the alkynol moiety. The 1,2-alkyl migration in the spiroindoleninium intermediate, generated after indole attack to the activated alkyne, is favored with gold(I) complexes and for electron-rich aromatic substituents at the homopropargylic position, whereas the 1,2-alkenyl shift is preferred when using gold(III) salts and for alkyl or non-electron-rich aromatic groups.
[ASAP] A Paradigm Shift in Catalysis: Electro- and Photomediated Nickel-Catalyzed Cross-Coupling Reactions
Accounts of Chemical Research
DOI: 10.1021/acs.accounts.3c00479
Vivianite for Phosphorus Recovery from Digester Supernatant in Wastewater Treatment Plants
Phosphate recovery in vivianite proved to have great potential for phosphorus recovery from digester supernatants. However, the size of the recovered vivianite was found to be very small (< 20 μm), impeding further processing. A process was developed to increase the crystal size of vivianite by controlled Fe2+ dosing and seeding effect, which can be a promising way for vivianite growth.
Abstract
Phosphorus (P) recovery by crystallization of vivianite in digester supernatant (DS) was investigated. A high recovery yield (> 90 %) was obtained with vivianite even for DS with low P concentration (74 mg L−1), as opposed to the formation of struvite and hydroxyapatite where the yield was lower than 50–60 %. Various strategies were tested to produce vivianite with large sizes and narrow size distribution, such as a controlled reagent dosing profile, self-seeded crystallization, and multistage cascade-seeded crystallization. The obtained results demonstrated that the main challenge in the development of vivianite P recovery is to promote crystal growth and to suppress secondary nucleation of vivianite during the crystallization process.
Recent advances in mitochondria‐localized luminescent ruthenium(II) metallodrugs as anticancer agents
Presently, the most effective way to transport drugs specifically to mitochondria inside the cells is of pharmacophoric interest as mitochondria are recognized as one of the most important targets for new drug design in cancer diagnosis. To date, there are many reviews covering the photophysical, photochemical, and anticancer properties of ruthenium(II) based metallodrugs owing to their high interest in biological applications. There are, however, no reviews specifically covering the mitochondria-localized luminescent Ru(II) complexes and their subsequent mitochondria-mediated anticancer activities. Therefore, this mini-review will describe the physicochemical basis for the mitochondrial accumulation of ruthenium complexes, their synthetic strategies to localize and monitor the mitochondria in living cells, and their related underlying anticancer results. Finally, we review the related areas from previous works describing the mitochondria-localized ruthenium complexes for the treatment of cancer-related diseases. Along with this, we also deliberate the perspectives and future directions for emerging more bifunctional Ru(II) complexes that can target, image, and kill tumors more efficiently in comparison with the existing mitochondria-targeted cancer therapeutics.
Photo‐Enhanced Oil Toxicity to Alcid Immune Function
Abstract
Oil spills are devastating to seabirds, causing high levels of mortality and toxic physiological effects, especially to immune function. Sunlight exposure can further enhance the toxicity of oil to marine species by generating photodegradation products. Photo-enhanced oil toxicity to marine birds has not been studied. Therefore, the goal of the present study was to investigate the toxicity and photo-enhanced toxicity of oil to lymphocyte proliferation, macrophage phagocytosis, and reactive oxygen species production in three alcid species, common murres (Uria aalge), tufted puffins (Fratercula cirrhata), and horned puffins (Fratercula corniculata). Intrinsic factors (species, age, and sex) had a more significant effect on lymphocyte proliferation than exposure to oil or photoactivated oil. Macrophage phagocytosis was significantly reduced in oil and photoactivated oil treatments, whereas hydrogen peroxide production was significantly increased. Interestingly, nonphotoactivated oil stimulated significantly more hydrogen peroxide than photoactivated oil. The results suggest that alcid immune function could be variably influenced during an oil spill depending on the species, sex, and age of the bird as well as the season and level of sunlight exposure. Environ Toxicol Chem 2023;00:1–11. © 2023 SETAC
Copper(I)‐Catalyzed Interrupted Click Reaction: Synthesis of 1,4,5‐Trisubstituted 5‐Chloro‐1,2,3‐Triazoles
A Cu(I)-catalyzed interrupted click reaction, using N-chlorophthalimide as electrophilic chlorine source, enabling the facile synthesis of 1,4,5-trisubstituted 5-chloro-1,2,3-triazoles in one step from readily available terminal alkynes and azides is reported. This approach allowed complete control of regioselectivities with a broad substrate scope. Furthermore, a novel epoxidation was developed using 5-chloro-triazole as substrate, which could be further applied in various organic transformations.
Abstract
5-Halo-1,2,3-triazoles are important scaffolds in organic chemistry, but current click reactions cannot produce 1,4,5-trisubstituted 5-chloro-1,2,3-triazoles in a simple way. Herein, we disclosed a Cu(I)-catalyzed interrupted click reaction, using N-chlorophthalimide as an electrophilic chlorine source, enabling the facile synthesis of 1,4,5-trisubstituted 5-chloro-1,2,3-triazoles in one step from readily available terminal alkynes and azides. Complete control of regioselectivities with a broad substrate scope was accomplished by this approach. Furthermore, a novel epoxidation was developed using 5-chloro-triazole as substrate, which could be further applied in various organic transformations.
Metal‐Free and Visible Light‐Induced Difunctionalizations of α‐CF3 Styrenes with Aryl Diazonium Salts and Hetero Nucleophiles
This concise protocol provided easy access to the α-CF3 tertiary alkyl ethers, alcohol and fluorides with good yields and excellent functional group tolerance. In addition, the four-component “SO2” insertion reaction also worked efficiently to produce the α-CF3, β-sulfonyl ethers in moderate to good yields. A radical-polar crossover coupling pathway was proposed for the C−O bond formation.
Abstract
Metal-free, visible light-induced difunctionalizations of α-CF3 styrenes with aryl diazonium salts and various hetero nucleophiles (ROH, H2O, N3 − and F−) are described. This concise protocol provided easy access to the α-CF3 tertiary alkyl ethers, alcohol and fluorides with good yields and excellent functional group tolerance. In addition, the four-component “SO2” insertion reaction also worked efficiently to produce the α-CF3, β-sulfonyl ethers in moderate to good yields. A radical-polar crossover coupling pathway was proposed for the C−O bond formation.